The present invention generally relates to methods and systems for generating oxygen and hydrogen gases from water, and, more particularly, to methods and systems for decomposing water into oxygen and hydrogen gases utilizing electrical forces and for separating an oxygen rich gas and a hydrogen rich gas from the water decomposition products. The oxygen rich gas and the hydrogen rich gas which are produced can then be utilized together in a variety of applications such as an energy source for engines, in fuel cells and the like, or the gases can be used separately for uses known in the art.
While the systems of the present invention will be primarily discussed hereinafter with reference to their use in conjunction with the decomposition of water and the separation of the resultant gases into an oxygen rich gas and a hydrogen rich gas, it should be recognized that their use and application are not thereby so limited. For example, the systems may be utilized in the decomposition of materials other than water including the decomposition of products into component gases and the subsequent separation of the component gases into one or more gaseous streams rich in one or more of component gases produced.
Various systems and devices are known in the art for producing oxygen from water and water vapor alone or as contained in various other gases such as waste gases. One such device is disclosed in U.S. Pat. No. 4,263,112 to Aylward which relates to an electrolytic converter for electrolytically converting water and moisture vapor to oxygen and hydrogen for use in a closed environment, particularly in connection with space travel. The device includes a housing providing a cell chamber, an inlet for water vapor and outlets for oxygen and hydrogen, the chamber containing a cell assembly including a gas pervious catalytic anode, a gas pervious cathode and an electrolyte containing matrix member between the anode and the cathode providing a conductive path. The anode specifically incorporates a catalytic coating to effect electrolysis of water vapor to hydrogen ions and oxygen, the catalytic coating containing iridium oxide.
Another such system is disclosed in U.S. Pat. No. 4,254 086 to Sanders which relates to system wherein a mixture of gases containing hydrogen is prepared by the dissociation of water vapor at an elevated temperature in excess of 350.degree. C. The resultant gaseous mixture containing hydrogen is then passed through a maze formed of a plurality of wafers of porous refractory material having a hydrogen permeable platinum group metal membrane. In the maze of wafers, hydrogen is separated to leave an oxygen enriched gas.
In addition, U.S. Pat. No. 4,747,925 to Hasebe et al discloses a system which simultaneously generates a mixed oxygen hydrogen gas by providing at least one pair of positive and negative electrodes opposed to each other in a tank of aqueous electrolyte solution which has a gas outlet. Also there are provided in the tank at least one pair of a magnetic member with the polarities thereof fixed in one and the same direction so that the forces therefrom will be directed upwardly in accordance with Fleming's left-hand rule in connection with the direction of the potential difference generated between the pair of electrodes. Oxygen and hydrogen produced in the system of the Hasbe patent are separated by interposing a diaphragm between the pair of electrodes and providing separate outlets for the respective gases.
The disclosures of the above patents are incorporated by references in their entireties.
Several disadvantages are inherent with such systems not including their relative complexity and relatively high costs associated therewith in term of equipment and energy costs. Among these disadvantages of conventional process for the electrolysis of water including those as noted above, there are the use of toxic compounds such as acids, acetate, ammonia, arsenic, asbestos, cadmium, carbon monoxide, caustic soda, chlorine, formaldehyde, methanol, mercury, phosphorous, cyanide and compounds of sulfur. As is readily apparent, use of these toxic materials involves environmental hazards as well as direct hazards to human safety.
In addition, many of the conventional processes and systems for the electrolysis of water use expensive precious metals and exotic organometallic compounds as catalysts or as composites of electrodes and electrolytic fluids. Furthermore, these processes and systems tend to utilize very high heat, very high pressures,, polychemical processes and the like and tend to operate slowly which pyramids equipment costs and magnifies equipment problems. In addition, such systems tend to be quite large and require significant amounts of energy for operation.